| AT91C_EMAC_HRESP;

}

//-----------------------------------------------------------------------------
/// Get the statstic information & reset it
/// \param pStats   Pointer to EmacStats structure to copy the informations
/// \param reset    Reset the statistics after copy it
//-----------------------------------------------------------------------------
void EMAC_GetStatistics(EmacStats *pStats, unsigned char reset)
{
    unsigned int ncrBackup = 0;

    trace_LOG(trace_DEBUG, "EMAC_GetStatistics\n\r");

    // Sanity check
    if (pStats == (EmacStats *) 0) {
        return;
    }

    ncrBackup = AT91C_BASE_EMAC->EMAC_NCR & (AT91C_EMAC_TE | AT91C_EMAC_RE);

    // Disable TX/RX
    AT91C_BASE_EMAC->EMAC_NCR = ncrBackup & ~(AT91C_EMAC_TE | AT91C_EMAC_RE);

    // Copy the informations
    memcpy(pStats, (void*)&EmacStatistics, sizeof(EmacStats));

    // Reset the statistics
    if (reset) {
        memset((void*)&EmacStatistics, 0x00, sizeof(EmacStats));
        AT91C_BASE_EMAC->EMAC_NCR = ncrBackup | AT91C_EMAC_CLRSTAT;
    }

    // restore NCR
    AT91C_BASE_EMAC->EMAC_NCR = ncrBackup;
}

//-----------------------------------------------------------------------------
/// Send a packet with EMAC.
/// If the packet size is larger than transfer buffer size error returned.
/// \param buffer   The buffer to be send
/// \param size     The size of buffer to be send
/// \param fEMAC_TxCallback Threshold Wakeup callback
/// \param fWakeUpCb   TX Wakeup
/// \return         OK, Busy or invalid packet
//-----------------------------------------------------------------------------
unsigned char EMAC_Send(void *pBuffer,
                        unsigned int size,
                        EMAC_TxCallback fEMAC_TxCallback)
{
    volatile EmacTxTDescriptor *pTxTd;
    volatile EMAC_TxCallback   *pTxCb;

    //trace_LOG(trace_DEBUG, "EMAC_Send\n\r");

    // Check parameter
    if (size > EMAC_TX_UNITSIZE) {

        trace_LOG(trace_ERROR, "-E- EMAC driver does not split send packets.");
        trace_LOG(trace_ERROR, " It can send %d bytes max in one packet (%u bytes requested)\n\r",
            EMAC_TX_UNITSIZE, size);
        return EMAC_TX_INVALID_PACKET;
    }

    // If no free TxTd, buffer can't be sent, schedule the wakeup callback
    if( CIRC_SPACE(txTd.head, txTd.tail, TX_BUFFERS) == 0) {
        return EMAC_TX_BUFFER_BUSY;

    }

    // Pointers to the current TxTd
    pTxTd = txTd.td + txTd.head;
    pTxCb = txTd.txCb + txTd.head;

    // Sanity check
    ASSERT((pTxTd->status & EMAC_TX_USED_BIT) != 0,
        "-F- Buffer is still under EMAC control\n\r");

    // Setup/Copy data to transmition buffer
    if (pBuffer && size) {
        // Driver manage the ring buffer
        memcpy((void *)pTxTd->addr, pBuffer, size);
    }

    // Tx Callback
    *pTxCb = fEMAC_TxCallback;

    // Update TD status
    // The buffer size defined is length of ethernet frame
    // so it's always the last buffer of the frame.
    if (txTd.head == TX_BUFFERS-1) {
        pTxTd->status =
            (size & EMAC_LENGTH_FRAME) | EMAC_TX_LAST_BUFFER_BIT | EMAC_TX_WRAP_BIT;
    }
    else {
        pTxTd->status = (size & EMAC_LENGTH_FRAME) | EMAC_TX_LAST_BUFFER_BIT;
    }

    CIRC_INC(txTd.head, TX_BUFFERS)

    // Tx packets count
    EmacStatistics.tx_packets++;

    // Now start to transmit if it is not already done
    AT91C_BASE_EMAC->EMAC_NCR |= AT91C_EMAC_TSTART;

    return EMAC_TX_OK;
}

//-----------------------------------------------------------------------------
/// Receive a packet with EMAC
/// If not enough buffer for the packet, the remaining data is lost but right
/// frame length is returned.
/// \param pFrame           Buffer to store the frame
/// \param frameSize        Size of the frame
/// \param pRcvSize         Received size
/// \return                 OK, no data, or frame too small
//-----------------------------------------------------------------------------
unsigned char EMAC_Poll(unsigned char *pFrame,
                        unsigned int frameSize,
                        unsigned int *pRcvSize)
{
    unsigned short bufferLength;
    unsigned int   tmpFrameSize=0;
    unsigned char  *pTmpFrame=0;
    unsigned int   tmpIdx = rxTd.idx;
    volatile EmacRxTDescriptor *pRxTd = rxTd.td + rxTd.idx;

    ASSERT(pFrame, "F: EMAC_Poll\n\r");

    char isFrame = 0;
    // Set the default return value
    *pRcvSize = 0;

    // Process received RxTd
    while ((pRxTd->addr & EMAC_RX_OWNERSHIP_BIT) == EMAC_RX_OWNERSHIP_BIT) {

        // A start of frame has been received, discard previous fragments
        if ((pRxTd->status & EMAC_RX_SOF_BIT) == EMAC_RX_SOF_BIT) {
            // Skip previous fragment
            while (tmpIdx != rxTd.idx) {
                pRxTd = rxTd.td + rxTd.idx;
                pRxTd->addr &= ~(EMAC_RX_OWNERSHIP_BIT);
                CIRC_INC(rxTd.idx, RX_BUFFERS);
            }
            // Reset the temporary frame pointer
            pTmpFrame = pFrame;
            tmpFrameSize = 0;
            // Start to gather buffers in a frame
            isFrame = 1;
        }

        // Increment the pointer
        CIRC_INC(tmpIdx, RX_BUFFERS);

        // Copy data in the frame buffer
        if (isFrame) {
            if (tmpIdx == rxTd.idx) {
                trace_LOG(trace_INFO,
                    "I: no EOF (Invalid of buffers too small)\n\r");

                do {

                    pRxTd = rxTd.td + rxTd.idx;
                    pRxTd->addr &= ~(EMAC_RX_OWNERSHIP_BIT);
                    CIRC_INC(rxTd.idx, RX_BUFFERS);
                } while(tmpIdx != rxTd.idx);
                return EMAC_RX_NO_DATA;
            }
            // Copy the buffer into the application frame
            bufferLength = EMAC_RX_UNITSIZE;
            if ((tmpFrameSize + bufferLength) > frameSize) {
                bufferLength = frameSize - tmpFrameSize;
            }

            memcpy(pTmpFrame, (void*)(pRxTd->addr & EMAC_ADDRESS_MASK), bufferLength);
            pTmpFrame += bufferLength;
            tmpFrameSize += bufferLength;

            // An end of frame has been received, return the data
            if ((pRxTd->status & EMAC_RX_EOF_BIT) == EMAC_RX_EOF_BIT) {
                // Frame size from the EMAC
                *pRcvSize = (pRxTd->status & EMAC_LENGTH_FRAME);

                // Application frame buffer is too small all data have not been copied
                if (tmpFrameSize < *pRcvSize) {
                    printf("size req %u size allocated %u\n\r", *pRcvSize, frameSize);

                    return EMAC_RX_FRAME_SIZE_TOO_SMALL;
                }

                trace_LOG(trace_INFO, "packet %d-%u (%u)\n\r", rxTd.idx, tmpIdx, *pRcvSize);
                // All data have been copied in the application frame buffer => release TD
                while (rxTd.idx != tmpIdx) {
                    pRxTd = rxTd.td + rxTd.idx;
                    pRxTd->addr &= ~(EMAC_RX_OWNERSHIP_BIT);
                    CIRC_INC(rxTd.idx, RX_BUFFERS);
                }
                EmacStatistics.rx_packets++;
                return EMAC_RX_OK;
            }
        }

        // SOF has not been detected, skip the fragment
        else {
           pRxTd->addr &= ~(EMAC_RX_OWNERSHIP_BIT);
           rxTd.idx = tmpIdx;
        }

        // Process the next buffer
        pRxTd = rxTd.td + tmpIdx;
    }

    //trace_LOG(trace_DEBUG, "E");
    return EMAC_RX_NO_DATA;
}

//-----------------------------------------------------------------------------
/// Registers pRxCb callback. Callback will be invoked after the next received
/// frame.
/// When EMAC_Poll() returns EMAC_RX_NO_DATA the application task call EMAC_Set_RxCb()
/// to register pRxCb() callback and enters suspend state. The callback is in charge
/// to resume the task once a new frame has been received. The next time EMAC_Poll()
/// is called, it will be successfull.
/// \param pRxCb            Pointer to callback function
//-----------------------------------------------------------------------------
void EMAC_Set_RxCb(EMAC_RxCallback pRxCb)
{
    rxTd.rxCb = pRxCb;
    AT91C_BASE_EMAC->EMAC_IER = AT91C_EMAC_RCOMP;
}

//-----------------------------------------------------------------------------
/// Remove the RX callback function.
/// This function is usually invoked from the RX callback itself. Once the callback
/// has resumed the application task, there is no need to invoke the callback again.
//-----------------------------------------------------------------------------
void EMAC_Clear_RxCb(void)
{
    AT91C_BASE_EMAC->EMAC_IDR = AT91C_EMAC_RCOMP;
    rxTd.rxCb = (EMAC_RxCallback) 0;
}

//-----------------------------------------------------------------------------
/// Registers TX wakeup callback callback. Callback will be invoked once several
/// transfer descriptors are available.
/// When EMAC_Send() returns EMAC_TX_BUFFER_BUSY (all TD busy) the application
/// task calls EMAC_Set_TxWakeUpCb() to register pTxWakeUpCb() callback and
/// enters suspend state. The callback is in charge to resume the task once
/// several TD have been released. The next time EMAC_Send() will be called, it
/// shall be successfull.
/// \param pTxWakeUpCb   Pointer to callback function
/// \param threshold     Minimum number of available transfer descriptors before pTxWakeUpCb() is invoked
/// \return              0= success, 1 = threshold exceeds nuber of transfer descriptors
//-----------------------------------------------------------------------------
char EMAC_Set_TxWakeUpCb(EMAC_WakeupCallback pTxWakeUpCb, unsigned short threshold)
{
    if (threshold <= TX_BUFFERS) {
        txTd.wakeupCb = pTxWakeUpCb;
        txTd.wakeupThreshold = threshold;
        return 0;
    }
    return 1;
}

//-----------------------------------------------------------------------------
/// Remove the TX wakeup callback function.
/// This function is usually invoked from the TX wakeup callback itself. Once the callback
/// has resumed the application task, there is no need to invoke the callback again.
//-----------------------------------------------------------------------------
void EMAC_Clear_TxWakeUpCb(void)
{
    txTd.wakeupCb = (EMAC_WakeupCallback) 0;
}